U

Uranium

Identification

CAS Number: 7440-61-1

Discovery Year: 1789

Discoverer: Martin Klaproth

Discovery Location: Germany

Properties

Atomic Mass: 238.02891 →Density: 19.1 g/cm³ →

Crust Abundance: 2.7 mg/kg

Crystal Structure: ORC

Atomic Dimensions

Atomic Radius: 175 pm →

Atomic Radius (Rahm): 283 pm

Covalent Radius: 196 pm →

Van der Waals Radius: 241 pm

Atomic Volume: 12.5 cm³/mol

Lattice Constant: 2.85 Å

Thermodynamics

Melting Point: 1405.5 K →Boiling Point: 4018 K →Specific Heat: 0.115 J/(g·K) →Thermal Conductivity: 27.5 W/(m·K) →Heat of Fusion: 12.6 kJ/mol →Heat of Vaporization: 417 kJ/mol →

Heat of Formation: 533 kJ/mol

Electronic Structure

Electron Config: [Rn] 5f3 6d 7s2

Block: f

Period: 7 →Electronegativity: 1.7 →

Oxidation States: +3, +4, +5, +6

Abundance & Geochemistry

Crust Abundance: 2.7 mg/kg

Sea Abundance: 0.0032 mg/L

Geochemical Class: rare earth & related

Goldschmidt Class: litophile

About

Uranium is a radioactive metal used as fuel in nuclear reactors and in nuclear weapons. It is naturally occurring and is the heaviest naturally abundant element.

Isotopes

U-238 238 99.27%

U-235 235 0.7204%

U-234 234 5.40e-3%